Background: Colorectal cancer (CRC) screening is a widely recommended, evidence-based preventive service that has traditionally been underused. Over the last decade, organized efforts by the Veterans Health Administration (VHA) to increase population screening for CRC among Veterans have been successful. But these population-centered efforts have increased screening utilization in a way that is not always concordant with screening benefit, particularly among older Veterans with comorbid illness. As patients get older and acquire health problems, the benefit of screening decreases and the potential harm of screening increases. Yet, existing population-centered efforts fail to adequately inform older, less healthy patients about this changing balance in benefit and harm, often yielding screening utilization that is discordant with benefit. Objectives: (1) to evaluate the impact of a 3-part Veteran-centered intervention (VC) versus pragmatic control (PC) on the frequency of CRC screening orders in a cluster-randomized controlled trial; (2) to perform a process evaluation to identify barriers and facilitators to implementation of Veteran-centered CRC screening as well as any unintended negative effects of our intervention; and, (3) to develop an implementable, Veteran- centered performance measure of CRC screening that incorporates an assessment of the quality of the decision-making process as well as whether or not screening was performed. Methods: We propose a study aimed at promoting more Veteran-centered CRC screening among individuals aged 70-75 with comorbid illness. In Aim 1, we will test a 3-part intervention consisting of: (1) a decision aid to help Veterans make informed screening decisions; (2) education for providers on how the benefits of screening vary according to age and health status; and (3) modification of performance measurement and clinical reminder systems to allow Veterans to make informed decisions about screening (including the informed decision to not be screened). The intervention will be tested in a pragmatic cluster-randomized controlled trial (cluster = provider) at two sites in the VA Ann Arbor Healthcare System. The primary outcome will be whether screening was ordered at the clinic visit. We will also assess the appropriateness of screening orders (i.e., whether screening is ordered in concordance with screening benefit), conceptual understanding of screening, elements of informed decision-making addressed in the screening discussion, and screening utilization at 6 months. In Aim 2, we will perform a process evaluation to inform future implementation efforts. Finally, in Aim 3, we will use the information collected in Aims 1 and 2 and work with an advisory panel of Veterans and an advisory panel of experts and partners from VHA operations to develop a more Veteran-centered performance measure of CRC screening. Impacts: This project will lead to an implementation study of Veteran-centered CRC screening on a broader scale, with the opportunity to measure the effects of such an approach. Furthermore, it will lead to the development of Veteran-centered performance measures that can be tested and potentially extended to other screening and preventive services. Lessons learned from this work may ultimately provide a model for delivering preventive care in a more Veteran-centered way.